module 4

Question 1

abiotic

Answer 1

Physical rather than biological in that they are not derived from living organisms.

Temperature, sunlight, water

Question 2

biotic

Answer 2

Related to living organisms

Plants, animals, bacteria

Question 3

Relationship types

Answer 3

Predation
Competition
Symbiosis

Question 4

Predator prey relationship

Answer 4

1. Prey numbers increase rapidly – fast reproduction rate
2. As a result of an increase in food, predator numbers also increase
3. This causes prey number to decrease – meaning the predators have less ‘food’
4. The predator population decreases as a result

Question 5

Types of symbiosis and examples

Answer 5

Mutualism: mutually beneficial interactions between members of the same or different species
–> Example: clownfish and sea anemones (anemone protects clownfish from predators, clownfish excretes nutrients for anemones)

Commensalism: an association between two organisms in which one benefits and the other derives neither benefit nor harm
–> Example: barnacles on whales

Parasitism: one organism, the parasite, lives off of another organism, the host, harming it and possibly causing death. The parasite lives on or in the body of the host
–> Example: tapeworms, fleas

Question 6

Australian megafauna theory: hunting

Answer 6

• Aboriginal people existed in Australia about 65000 years ago
• They used fire to burn back the bush (fire and stick farming technique which involved burning vegetation to regenerate the grasses for the animals they could hunt)
• This method meant they hunted the Australian megafauna which were larger and slower compared to other animals
• The megafauna were wiped out and the smaller faster animals escaped to survive and reproduce
• Additionally, man’s introduction of the dingo from Asia led to a decrease in the diversity of carnivore predators

Question 7

Australian megafauna theory: climate change

Answer 7

• The ice age caused the continent to dry out
• Drying climates caused rainforests to reduce, they were replaced by eucalypt forests
• Less water was returned to the atmosphere and falling in monsoon rains as eucalypt tree were less efficient at retaining water
• Lack of monsoon rains caused rivers to dry up, causing a change in flora and fauna
• The result of this new hotter, drier climate caused fires to break out

Question 8

Types of competition

Answer 8

intraspecific: between members of the same species
interspecific: between members of a different species

Question 9

What do sampling techniques measure?

Answer 9

Abundance, distribution, density of a population

Question 10

Define abundance

Answer 10

how many members of the species live throughout the ecosystem
- effected by immigration / emigration of species, influx of predators or prey, change in structure of habitat, weather and seasonal changes

Question 11

Define Distribution

Answer 11

the area where it is found
- gives clues about how it is interacting with the environment
- differs due to variance in the environment (as a result of temperature, abiotic and biotic factors determining survival)

Question 12

Sampling techniques

Answer 12

Transects, quadrat sampling, capture-recapture